/**********
This library is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)

This library is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
more details.

You should have received a copy of the GNU Lesser General Public License
along with this library; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
**********/
// "liveMedia"
// Copyright (c) 1996-2018 Live Networks, Inc.  All rights reserved.
// An abstraction of a network interface used for RTP (or RTCP).
// (This allows the RTP-over-TCP hack (RFC 2326, section 10.12) to
// be implemented transparently.)
// C++ header

#ifndef _RTP_INTERFACE_HH
#define _RTP_INTERFACE_HH

#ifndef _MEDIA_HH

#include <Media.hh>

#endif
#ifndef _GROUPSOCK_HH

#include "../../groupsock/include/Groupsock.hh"

#endif

// Typedef for an optional auxilliary handler function, to be called
// when each new packet is read:
typedef void AuxHandlerFunc(void *clientData, unsigned char *packet,
                            unsigned &packetSize);

typedef void ServerRequestAlternativeByteHandler(void *instance, u_int8_t requestByte);
// A hack that allows a handler for RTP/RTCP packets received over TCP to process RTSP commands that may also appear within
// the same TCP connection.  A RTSP server implementation would supply a function like this - as a parameter to
// "ServerMediaSubsession::startStream()".

class tcpStreamRecord {
public:
    tcpStreamRecord(int streamSocketNum, unsigned char streamChannelId,
                    tcpStreamRecord *next);

    virtual ~tcpStreamRecord();

public:
    tcpStreamRecord *fNext;
    int fStreamSocketNum;
    unsigned char fStreamChannelId;
};

class RTPInterface {
public:
    RTPInterface(Medium *owner, Groupsock *gs);

    virtual ~RTPInterface();

    Groupsock *gs() const { return fGS; }

    void setStreamSocket(int sockNum, unsigned char streamChannelId);

    void addStreamSocket(int sockNum, unsigned char streamChannelId);

    void removeStreamSocket(int sockNum, unsigned char streamChannelId);

    static void setServerRequestAlternativeByteHandler(UsageEnvironment &env, int socketNum,
                                                       ServerRequestAlternativeByteHandler *handler,
                                                       void *clientData);

    static void clearServerRequestAlternativeByteHandler(UsageEnvironment &env, int socketNum);

    Boolean sendPacket(unsigned char *packet, unsigned packetSize);

    void startNetworkReading(TaskScheduler::BackgroundHandlerProc *
    handlerProc);

    Boolean handleRead(unsigned char *buffer, unsigned bufferMaxSize,
            // out parameters:
                       unsigned &bytesRead, struct sockaddr_in &fromAddress,
                       int &tcpSocketNum, unsigned char &tcpStreamChannelId,
                       Boolean &packetReadWasIncomplete);
    // Note: If "tcpSocketNum" < 0, then the packet was received over UDP, and "tcpStreamChannelId"
    //   is undefined (and irrelevant).


    // Otherwise (if "tcpSocketNum" >= 0), the packet was received (interleaved) over TCP, and
    //   "tcpStreamChannelId" will return the channel id.

    void stopNetworkReading();

    UsageEnvironment &envir() const { return fOwner->envir(); }

    void setAuxilliaryReadHandler(AuxHandlerFunc *handlerFunc,
                                  void *handlerClientData) {
        fAuxReadHandlerFunc = handlerFunc;
        fAuxReadHandlerClientData = handlerClientData;
    }

    void forgetOurGroupsock() { fGS = NULL; }
    // This may be called - *only immediately prior* to deleting this - to prevent our destructor
    // from turning off background reading on the 'groupsock'.  (This is in case the 'groupsock'
    // is also being read from elsewhere.)

private:
    // Helper functions for sending a RTP or RTCP packet over a TCP connection:
    Boolean sendRTPorRTCPPacketOverTCP(unsigned char *packet, unsigned packetSize,
                                       int socketNum, unsigned char streamChannelId);

    Boolean sendDataOverTCP(int socketNum, u_int8_t const *data, unsigned dataSize,
                            Boolean forceSendToSucceed);

private:
    friend class SocketDescriptor;

    Medium *fOwner;
    Groupsock *fGS;
    tcpStreamRecord *fTCPStreams; // optional, for RTP-over-TCP streaming/receiving

    unsigned short fNextTCPReadSize;
    // how much data (if any) is available to be read from the TCP stream
    int fNextTCPReadStreamSocketNum;
    unsigned char fNextTCPReadStreamChannelId;
    TaskScheduler::BackgroundHandlerProc *fReadHandlerProc; // if any

    AuxHandlerFunc *fAuxReadHandlerFunc;
    void *fAuxReadHandlerClientData;
};

#endif
